The orbital motion of the Quintuplet cluster - a common origin for the Arches and Quintuplet clusters?

Abstract

We investigate the orbital motion of the Quintuplet cluster near the Galactic center with the aim of constraining formation scenarios of young, massive star clusters in nuclear environments. Three epochs of adaptive optics high-angular resolution imaging with Keck/NIRC2 and VLT/NACO were obtained over a time baseline of 5.8 years, delivering an astrometric accuracy of 0.5-1 mas/yr. Proper motions were derived in the cluster reference frame and were used to distinguish cluster members from the majority of field stars. Fitting the cluster and field proper motion distributions with 2D gaussian models, we derive the orbital motion of the cluster for the first time. The Quintuplet is moving with a 2D velocity of 132 +/- 15 km/s with respect to the field along the Galactic plane, which yields a 3D orbital velocity of 167 +/- 15 km/s when combined with the previously known radial velocity. From a sample of 119 stars measured in three epochs, we derive an upper limit to the velocity dispersion in the core of the Quintuplet cluster of sigma_1D < 10 km/s. Knowledge of the three velocity components of the Quintuplet allows us to model the cluster orbit in the potential of the inner Galaxy. Comparing the Quintuplet's orbit with the Arches orbit, we discuss the possibility that both clusters originated in the same area of the central molecular zone. [abridged]

40 pages, 12 figures, accepted for publication in ApJ

References in corpus (18)

• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• Physical Properties of Wolf-Rayet Stars
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• The UKIDSS Galactic Plane Survey
• The structure of the nuclear stellar cluster of the Milky Way
• The most massive stars in the Arches cluster
• Gas flow models in the Milky Way embedded bars
• A SINFONI view of Galaxy Centers: Morphology and Kinematics of five Nuclear Star Formation Rings
• A Connection between Star Formation in Nuclear Rings and their Host Galaxies
• The proper motion of the Arches cluster with Keck Laser-Guide Star Adaptive Optics
• Internal dynamics and membership of the NGC 3603 Young Cluster from microarcsecond astrometry
• Pinwheels in the Quintuplet Cluster
• The Quintuplet Cluster I. A K-band spectral catalog of stellar sources
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• The Quintuplet Cluster II. Analysis of the WN stars
• Nuclear Star-Forming Ring of the Milky Way: Simulations
• Isolated massive stars in the Galactic center: The dynamic contribution from the Arches and Quintuplet star clusters
• Evolution of Star Clusters near the Galactic Center: Fully Self-consistent N-body Simulations

Cited by in corpus (18)

• The dynamical evolution of molecular clouds near the Galactic Centre - I. Orbital structure and evolutionary timeline
• Cloud-cloud collisions and triggered star formation
• The Survey of Water and Ammonia in the Galactic Center (SWAG): Molecular Cloud Evolution in the Central Molecular Zone
• Simulations of the Milky Way's central molecular zone -- II. Star formation
• High-energy particles and radiation in star-forming regions
• The stellar mass distribution of the Milky Way's bar: an analytic model
• ALMA Observations of Massive Clouds in the Central Molecular Zone: Jeans Fragmentation and Cluster Formation
• The formation of UCDs and massive GCs: Quasar-like objects for testing for a variable stellar initial mass function (IMF)
• Kinematics of classical Cepheids in the Nuclear Stellar Disk
• The formation of early-type galaxies through monolithic collapse of gas clouds in Milgromian gravity
• The Quintuplet Cluster: Extended Structure and Tidal Radius
• Constraining the population of isolated massive stars within the Central Molecular Zone
• M0.20-0.033: An Expanding Molecular Shell in the Galactic Center Radio Arc
• Stellar Populations in the Transition Region of Nuclear Star Cluster and Nuclear Stellar Disc
• First results from a large-scale proper motion study of the Galactic Centre
• Measuring the Orbits of the Arches and Quintuplet Clusters using HST and Gaia: Exploring Scenarios for Star Formation Near the Galactic Center
• The absolute proper motions of the Arches and Quintuplet clusters
• Variable Stars in the Quintuplet stellar cluster with the VVV Survey